scholarly journals Study for Prediction of Contact Forces between Wheel and Rail Using Vibrational Transfer Function of the Scaled Squeal Noise Test Rig

2016 ◽  
Vol 19 (1) ◽  
pp. 20-28 ◽  
Author(s):  
Junheon Lee ◽  
Jiyong Kim ◽  
Eun Ji ◽  
Daeyong Kim ◽  
Kwanju Kim
Keyword(s):  
Transfer Function ◽  
Contact Forces ◽  
Test Rig ◽  
Noise Test ◽  
Squeal Noise

scholarly journals The uncertainty in stiffness and damping of an automotive vehicle’s trim-structure mounts and its effect on the variability of the vibration transfer function

2017 ◽  
Vol 232 (15) ◽  
pp. 2587-2598 ◽  
Author(s):  
Ali Abolfathi ◽  
Dan J O’Boy ◽  
Stephen J Walsh ◽  
Amy M Dowsett ◽  
Stephen A Fisher
Keyword(s):  
Boundary Condition ◽  
Transfer Function ◽  
Dynamic Response ◽  
Transfer Functions ◽  
Effective Stiffness ◽  
3D Printer ◽  
Structural Elements ◽  
Test Rig ◽  
Manufacturing Tolerances ◽  
Stiffness And Damping

A large number of plastic clips are used in an automotive vehicle to connect the trim to the structure. These are small clips with very small masses compared to the structural elements that they connect together; however, the uncertainty in their properties can affect the dynamic response. The uncertainty arises out of their material and manufacturing tolerances and more importantly the boundary conditions. A test rig has been developed that can model the mounting condition of the clips. This allows measurement of the range of their effective stiffness and damping. Initially, the boundary condition at the structure side is replicated. The variability is found to be 7% for stiffness and 8% for damping. In order to simulate the connection of the trim side, a mount is built using a 3D printer. The variability due to the boundary condition on both sides was as large as 40% for stiffness and 36% for damping. A Monte Carlo simulation is used in order to assess the effect of the uncertainty of the clips’ properties on the vibration transfer functions of a door assembly. A simplified connection model is used in this study where only the axial degree of freedom is considered in connecting the trim to the door structure. The uncertainty in the clip stiffness and damping results in a variability in the vibration transfer function which is frequency dependent and can be as high as 10% at the resonant peaks with higher values at some other frequencies. It is shown that the effect of the uncertainty in the clips effective damping is negligible and the variability in the dynamic response is mainly due to the uncertainty in the clip’s stiffness. Furthermore, it is shown that the variability would reduce either by increasing or decreasing the effective stiffness of the clips.

Development of experimental vibro-acoustic transfer function for a system with combined rolling-sliding motion

2021 ◽  
Vol 263 (5) ◽  
pp. 1505-1515
Author(s):  
Kumar Milind Rewanand Shripad ◽  
Sriram Sundar
Keyword(s):  
Transfer Function ◽  
Noise Exposure ◽  
Acoustic Pressure ◽  
Acoustic Noise ◽  
Contact Forces ◽  
Sliding Contact ◽  
Direct Technique ◽  
Cam Follower ◽  
Acoustic Transfer Function ◽  
Contact Parameters

Combined rolling-sliding contact is present in popular non-linear systems such as cam-follower, gears, clutches, and brakes. These systems produce significant noise due to complex contact between the components during operation. The noise generated is a strong function of the contact parameters and excitation to the system. The objective of this study is to develop a transfer function to quantify the vibro-acoustic noise for various contact conditions. Acceleration, reaction forces, and acoustic pressure measurements are made on a cam-follower setup with combined rolling-sliding contact. Experiments are performed under different conditions of friction, lubrication, load, and speed. Contact forces are back-calculated using the kinematics. The transfer function relating the acoustic pressure to different forces is estimated. It is observed that the contact parameters govern the transfer function and hence the vibro-acoustic systems. The developed transfer function is useful in designing better sub-systems with combined rolling-sliding contact to reduce noise exposure, as a direct technique to relate the contact parameters to the noise does not exist. This study can be extended to other complex systems such as gears and clutches.

An Automotive Supercharger Noise Test Rig Incorporating Torsional Excitation

2005 ◽  
Author(s):  
Jason C. Koval ◽  
Andrew W. Fedewa ◽  
Keith A. Hollman ◽  
Douglas G. Woolcott
Keyword(s):  
Test Rig ◽  
Torsional Excitation ◽  
Noise Test

scholarly journals Performance Analysis of Piezoelectric Actuators in Railway Wheel Squealing Noise Mitigation

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Seyed Rahim Marjani ◽  
Davood Younesian
Keyword(s):  
Sound Pressure ◽  
Near Field ◽  
Pressure Level ◽  
Contact Forces ◽  
Railway Track ◽  
Noise Mitigation ◽  
Method Performance ◽  
The Time Domain ◽  
Squeal Noise ◽  
Railway Wheels

Application of a shunted piezoelectric system in reduction of the squeal noise level in railway wheels is studied. A wheel squeal model including the railway track, wheel, and nonlinear interaction contact forces is taken into account in the time domain. Consequent vibration of the wheel is calculated at incident of sharp curve passing. The sound pressure level (SPL) of the noise is then calculated by an analytical method. Performance of different shunt circuits including the R (resistance) and RL (resistance inductance) is evaluated in different frequency ranges. A new methodology is proposed to achieve multimode damping. According to results, the SPL of wheel squeal noise can effectively get reduced by the proposed method, up to 5 dB at near-field and 10 dB at far-field.

Daimler’s new exterior noise test rig for all-wheel-drive vehicles

ATZ worldwide ◽  
2012 ◽  
Vol 114 (5) ◽  
pp. 26-32
Author(s):  
Harald Behrendt ◽  
Ralf Sperber ◽  
Konrad Pux ◽  
Ulrich Losner ◽  
Hartmut Bathelt
Keyword(s):  
Test Rig ◽  
Wheel Drive ◽  
Noise Test

scholarly journals Vibration Separation Methodology Compensated by Time-Varying Transfer Function for Fault Diagnosis of Non-Hunting Tooth Planetary Gearbox

Sensors ◽  
2022 ◽  
Vol 22 (2) ◽  
pp. 557
Author(s):  
Shuiguang Tong ◽  
Junjie Li ◽  
Feiyun Cong ◽  
Zilong Fu ◽  
Zheming Tong
Keyword(s):  
Transfer Function ◽  
Vibration Signal ◽  
Time Varying ◽  
Relative Location ◽  
Test Rig ◽  
Planetary Gearbox ◽  
Evaluation Indicator ◽  
Planet Gear ◽  
Localized Faults ◽  
Further Development

Due to planetary movement of planet gears, the vibration signal perceived by a stationary sensor is modulated and difficult to diagnose. This paper proposed a vibration separation methodology compensated by a time-varying transfer function (TVTF-VS), which is a further development of the vibration separation (VS) method in the diagnosis of non-hunting tooth planetary gearboxes. On the basis of VS, multi-teeth VS is proposed to extract and synthesize the meshing signal of a planet gear using a single transducer. Considering the movement regularity of a planetary gearbox, the time-varying transfer function (TVTF) is represented by a generalized expression. The TVTF is constructed using a segment of healthy signal and an evaluation indicator is established to optimize the parameters of the TVTF. The constructed TVTF is applied to overcome the amplitude modulation effect and highlight fault characteristics. After that, experiments with baseline, pitting, and compound localized faults planet gears were conducted on a non-hunting tooth planetary gearbox test rig, respectively. The results demonstrate that incipient failure on a planet gear can be detected effectively, and relative location of the local faults can be determined accurately.

REDUCTION OF DISC BRAKE SQUEAL NOISE USING CONSTRAINED LAYER DAMPERS

2017 ◽  
Vol 79 (7-4) ◽  
Author(s):  
S. Arvin Rao ◽  
Muhamad Anuwar Jusoh ◽  
Abd Rahim Abu Bakar ◽  
Mohd Kameil Abdul Hamid ◽  
Khidzir Zakaria
Keyword(s):  
Standard Procedure ◽  
Brake Disc ◽  
Hydraulic Pressure ◽  
Disc Brake ◽  
Butadiene Rubber ◽  
Brake Squeal ◽  
Noise Test ◽  
Prevention Methods ◽  
Squeal Noise ◽  
Brake Noise

Brakes squeal has remained to be one of the major NVH challenges in brake system design and development. It has been a concern for automotive industry for decade. Brake researchers have proposed many brake squeal reduction and prevention methods in order to overcome and reduce the squeal that emanates from the brake disc systems. In this paper, the effectiveness of constrained layer dampers (CLD) in reducing disc brake squeal noise was investigated. CLD isolates the brake squeal noise through shear deformations of the viscoelastic materials. Two sets of brake tests were conducted using the brake test dynamometer with the application of CLD. Two different types of CLD were used which are three-layer constrained layer damper and four-layer constrained layer damper. Squeal tests were carried out using brake noise test rig based on the global standard procedure SAE J2521. From the test, four-layer CLD configuration works more efficient than three-layer CLD configuration. CLD made up of nitrile butadiene rubber, silicone rubber and mild steel proved to be the most effective noise insulator at hydraulic pressure range of 5 bar to 30 bar and temperature range of 50oC to 200oC with a maximum noise reduction of 11.3 dBA. Thus, CLD technique was proven to be an effective method in reducing brake squeal noise.

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